An antitheft device is mounted in a vehicle to prevent theft of articles in the vehicle cabin, as well as of the vehicle itself, when the vehicle is parked. The antitheft device detects when a door is unlocked (i.e., when the door lock is in the unlocked position) by any means other than the use of a legitimate key, or when a door or hood is opened (i.e., when a courtesy switch is on).
Also, when an individual that is up to no good (hereinafter simply referred to as a “suspicious individual”) attempts to enter the vehicle by breaking a glass window, vibration or sound from the glass breaking during entry is detected by a sensor, for example. Also, when someone who has illicitly entered (i.e., broken into) the vehicle (hereinafter simply referred to as “an intruder”) is in the vehicle, a moving body (i.e., the intruder) in the vehicle cabin is detected based on a disturbance in ultrasonic waves or radio waves received by an ultrasonic wave or radio wave transceiver fixed to the rearview mirror or the like. Also, to prevent the vehicle itself from being stolen by being moved by a tow truck or the like, an inclination sensor, which detects the inclination of the vehicle, detects the inclination of the vehicle when one end of the vehicle is raised.
Moreover, in addition to detecting straightforward tampering such as that described above, some antitheft devices also detect when a battery is disconnected and then reconnected again as tampering. This is because it is theoretically possible for one person to disconnect the battery, which would deactivate the antitheft device, and another person to break into the vehicle while the antitheft device is deactivated, and then have the person reconnect the battery.
If such tampering is detected, the antitheft device activates to deter theft, e.g., sounds the horn and blinks the hazard lights to scare off suspicious individuals near the vehicle, and takes a picture of the them and transmits the image data to the owner of the vehicle.
Some vehicles are equipped with a remote operating apparatus that enables the user of the vehicle to operate an onboard device from a distance via a terminal. For example, the user is able to send a signal to the remote operating apparatus from a terminal shortly before getting into the vehicle (before he or she is approaches the vehicle) to start the engine to warm it up beforehand, or turn on the air-conditioner so that the vehicle is a comfortable temperature when he or she gets in.
However, because a parked vehicle is in a state ready to detect tampering, activating such a remote operating apparatus may cause the following problems. For example, the antitheft device may erroneously activate as a result of falsely detecting vibrations of the vehicle caused by the engine starting as vibrations caused by tampering by a suspicious individual. Or, the reflected ultrasonic waves or radio waves may be disrupted by electromagnetic waves or blowing air produced by the air-conditioner when it is turned on, and the antitheft device may erroneously activate as a result of falsely detecting that disruption as a disruption caused by an intruder.
Also, when the engine or the air-conditioner is turned on by the remote operating apparatus, the battery voltage drops due to cranking and then rises again when the engine speed stabilizes. This drop and rise in voltage may be mistaken for the battery being disconnected and then reconnected again, which would cause the antitheft device to erroneously activate.
Regarding this, Japanese Patent Application Publication No. 2002-79911 (JP-A-2002-79911) describes technology that reduces such erroneous activation of an antitheft device that is caused by such remote operation. When an engine is started remotely, the technology described in JP-A-2002-79911 stores the engine startup state indicative of the fact that the engine has been started, and reduces the sensitivity of a tampering detection sensor. Storing the engine startup state makes it possible to prevent battery disconnection and reconnection from being falsely detected when the battery voltage temporarily drops due to cranking. Also, reducing the sensitivity of the detection sensor makes it possible to prevent vibrations caused by starting the engine or air blown from the air-conditioner when it is turned on from being falsely detected as an intruder.
However, with the technology described in JP-A-2002-79911, when the air-conditioner is turned on remotely without starting the engine, the engine startup state is unable to be stored so the air blown from the air-conditioner when the air-conditioner is turned on may end up being falsely detected as an intruder.